I think they are? Just like AxA uses Answer and the announcement also changes for True DxD. I remember people used to argue about whether DxD Issei was using Boost, but he did outright say he used it against Vidar.
Then it doesn’t make much sense for Issei to stop using Boost for some reason.
I consider D∞D and Answer to just be channeling the power of Infinity and Dreams respectively, we don't assume the LLLLL Sound from Vali to be him using Divide, it's him channeling the demonic power of his heritage.
Ex: I aimed the cannons embedded in my four wings in front of me! There were two above my shoulders, and two under my armpits; the barrel of the cannons widened!
The infinite power of Ophis was concentrated into the cannons.
“[<<D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D !!!!!!!!>>]”
A [∞] symbol emerged on every one of my gems, and they alternated with flashes of red and black light. DOOOO…the cannons were charging up. Ophis —
The Dragon God of Infinity’s power was being focused.
“GOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!”
“<<[∞ Blaster !!!!!!]>>”
Ex:
They quietly began to hum, as the power of infinity gathered at each of the muzzles!
<<How interesting! Let’s finish this now, Sekiryuutei!>>
Apophis unleashed an extraordinarily large ball of darkness from his mouth! Even I would suffer immense damage if I was hit by that in my current state! A voice resounded from all of my gems.
“[<<D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D D∞D !!!!!!!!>>]”
An [∞] symbol appeared on all of the gems of my armour, as the colours of red and black flashed alternatingly.
“Goooooooooooooooooooooooooooooo!”
“[<< ∞ Blaster!!!!!! >>]”
Ex: “—
Great Red’s power, it’s the manifestation of that answer.”
—.
…
Great Red’s power… The one that resides within me, it’s answer, manifestation…?
EX: When I asked, it seemed like communication got established and
I could hear the answer.
《I have some questions too, but suddenly, your Skithblathnir activated. Ophis and her other self said they were going to take him...and suddenly, they teleported.》
Ex: Yes. Information was flowing. Above all, I understood the real identity of this Ryuuteimaru. What Ophis was saying,
the power of Great Red, the manifestation of that answer... Using my body as a medium, Ryuuteimaru scooped it out and embodied the part which otherwise would be limited by my body. And by connecting with that, this form —
the manifestation of Great Red's power was complete!
Ex: It was not yet complete! After all, it just came out of the cocoon! Wait, Seekvaira-san's voice sounded really excited! W-Well, that’s fine! Anyway, if I didn’t do something, everyone would be thrown into the Abyss! In my mind — I thought about going ahead!
Then, Ryuuteimaru, the huge flying object, also advanced. ...It works! If I think, this guy answers! I put the target on the sphere full of eyeballs in front of me and increased the speed! A booster connected to Ryuuteimaru spurted aura greatly and bounced forward with great impulse! Seeing this, Tartarus opened all eyes.
Ex: "AnswerArms"
Ex: "...That is, your familiar's grown form, and
the answer of Great Red's power...I suppose.”
"...I don't know how to use it from now on, but I think it would be nice if it’s something worthy of that
'answer'.”
Ex:
Vali channelled his power into his wings of Lucifer.
[[[LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL]]]
A faulty-sounding noise once again blared out from the gems of his armour.
And I don't believe DDD or D∞D are ever used as replacements for Boost. Similar to how "Bust" is portrayed differently.
